Idler recoil and track adjuster with encapsulated spring-retention arrangement, and method of assembly and disassembly thereof

ABSTRACT

A spring retention arrangement includes an inner casing, within which the spring is disposed, and an outer casing within which the inner casing is disposed. A retaining member is securable to both the inner casing and outer casing to enclose the spring, and means are provided to ensure that the retaining member cannot be removed from the outer casing without first disattaching the retaining member from the inner casing, allowing the spring to extend to its free length while still enclosed.

United States Patent 11 1 1 1 3,915,510 Alexander Oct. 28, 1975 1 IDLER RECOIL AND TRACK ADJUSTER 2,631,031 3/1953 Davis 267/70 WITH ENCAPSULATED 3,332,725 7/1967 Rewsma 305/10 SPRING-RETENTION ARRANGEMENT, AND METHOD OF ASSEMBLY AND DISASSEMBLY THEREOF George F. Alexander, Pekin, Ill.

Assignee: Caterpillar Tractor Co., Peoria, Ill.

Filed: Jan. 30, 1975 Appl. No.: 545,448

Inventor:

US. Cl 305/10; 267/70 Int. Cl. B62D 55/30 Field of Search 305/10, 31; 267/70, 71,

References Cited UNITED STATES PATENTS Luepsinger 267/70 Primary ExaminerPhilip Goodman Attorney, Agent, or FirmPhiillips, Moore, Weissenberger, Lempio & Strabala 5 7] ABSTRACT A spring retention arrangement includes an inner casing, within which the spring is disposed, and an outer casing within which the inner casing is disposed. A retaining member is securable to both the inner casing and outer casing to enclose the spring, and means are provided to ensure that the retaining member cannot be removed from the outer casing without first disattaching the retaining member from the inner casing, allowing the spring to extend to its free length while still enclosed.

8 Claims, 2 Drawing Figures US. Patent Oct. 28, 1975 IDLER RECOIL AND TRACK ADJUSTER WITH ENCAPSULATED SPRING-RETENTION ARRANGEMENT, AND METHOD OF ASSEMBLY AND DISASSEMBLY THEREOF BACKGROUND OF THE INVENTION This invention relates to idler recoil mechanisms, and more particularly, to an idler recoil mechanism which incorporates a spring which may be handled in an extremely safe and efficient manner.

Disclosed in application Ser. No. 507,263, application Ser. No. 507,264, U.S. Pat. No. 3,829,172 (all assigned to the assignee of the present invention), and US. Pat. No. 2,818,311 are various systems which incorporate springs for allowing idler recoil in a tractor or the like. In each case, it is to be noted that ring means disposed in appropriate grooves are provided for holding spring means in a compressed state during assembly, disassembly, or operation of the system. While such ring means have been found effective in properly retaining such spring means, it is to be understood that a spring of the type disclosed, in its assembled state, may apply a force of many tons on the spring retaining members. A study of the systems cited above reveals that, if a high degree of care is used in assembling and disassembling the spring retaining means thereof, such systems can be handled in a relatively safe manner. However, it will also be seen that such arrangements, if handled in an inappropriate manner by one who is relatively inexperienced, can produce certain dangerous conditions wherein the spring means would be allowed to extend at an inappropriate time, resulting in a potentially hazardous condition.

SUMMARY OF THE INVENTION It is accordingly an object of this invention to provide a recoil spring arrangement in which the spring means are prevented from undesirably extending from a compressed state thereof. 1

It is a further object-of this invention to provide a recoil spring arrangement which, while fulfilling the above object, provides that the spring means are fully enclosed until the free extended length thereof has been reached.

It is a still further object of this invention to provide a recoil spring arrangement which, while fulfilling the above objects, is extremely simple in design and use.

It is also an object of this invention to provide a method of assembling and disassembling a spring retention arrangement, which method is practiced in an extremely safe and efficient manner.

Broadly stated, the invention comprises a springretention arrangement comprising a first casing within which the spring arrangement is disposed and defining a wall against which one end of the spring is positionable. A second casing is positioned generally about the first casing. Further included are a retaining member, and means for releasably securing the retaining member to the first casing, so that the spring is in a compressed state applying force to the wall and retaining member with the retaining member so secured to the first casing. Means are included for releasably securing the retaining member to the second casing. Means are associated with the retaining member for providing that the retaining member may be released from the state wherein it is secured to the second casing only upon release of the retaining member from the first casing, al-

lowing the spring to extend to a state wherein the wall and retaining member are free of spring force thereon.

Also broadly stated, the invention comprises a method of assembling a spring-retention arrangement comprising positioning a spring in a first casing defining a wall, and positioning the first casing generally within a second casing. A retaining member is secured to the second casing, and the spring is compressed within the first casing against the wall, independently of the retaining member. The retaining member is secured to the first casing, and the independent compression of the spring is released to allow the spring to apply force to the wall and retaining member.

BRIEF DESCRIPTION OF THE DRAWINGS There and other objects of the invention will become apparent from a study of the following specification and drawings, in which:

FIG. 1 is a side elevation of a vehicle incorporating the invention; and

FIG. 2 is a sectional view of the recoil system of FIG. 1, incorporating the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Shown in FIG. 1 is a vehicle which includes a recoil system for an idler, such recoil system incorporating the present invention.

Shown in FIG. 1 is a vehicle 10 incorporating a recoil system 12 for an idler 14 of the vehicle 10. The recoil system 12 is shown in detail in FIG. 2, and is designed and operated substantially in accordance with the system disclosed in application Ser. No. 507,263 (assigned to the assignee of the present invention), and reference is made to such application for a complete understanding of the operation of such recoil system in its assembled state.

In the present invention, the spring 16 in the operating state shown in FIG. 2 is loaded to an extent of approximately 63,500 pounds, and it will be understood that such spring 16 must not only be retained in operating condition in a safe manner, but must be capable of being handled during assembly and disassembly of the apparatus in an extremely safe manner, as the sudden undesirable extension of such a spring could cause great injury and damage.

In the assembly of the particular spring system of the present invention, the spring 16 is disposed within a casing 18 which defines an end wall 20 against which one end of the spring 16 is positionable. The casing 18 also includes an inner tubular portion 22 which defines a threaded bore 24. A collar 26 is positioned within the casing 18 to contact the other end of the spring 16. The casing 18 is positioned within a casing 28, so that the casing 28 is positioned generally about the casing 18. A sleeve 30 is inserted within the-casing 28 against the collar 26.

A retaining member 32 is secured to the casing 28, by means of bolts 34 disposed through apertures defined by the retaining member 32 and in threaded engagement with the casing 28. Through such bolts 34, the retaining member 32 is selectively secured to the casing 28. In such state, the spring 16 is in its fully extended state, so that the casing 18 is drawn away from the retaining member 32.

A threaded rod (not shown.) attached to a ram or the like is then threaded into the threaded portion 24 of the tubular portion 22, and is retracted to move the wall of the casing 18 leftward, the sleeve contacting the retaining member 32 to limit leftward movement of the collar 26, so that the spring 16 is compressed within the casing 28 between the wall 20 and the collar 26. A flange member 36 is then fitted against the retaining member 32, and the flange member 36 and retaining member 32 define apertures through which bolts 38 are disposed and in threaded engagement with the casing 18. Through such means, the retaining member 32 is selectively secured to the casing 18. Compression of the spring 16 by means of the ram may then be released, and the spring 16 allowed to extend between the wall 20 and the collar 26. In such state, the spring 16 is in a compressed state applying force to the wall 20 and retaining member 32 (through the collar 26 and sleeve 30).

It is to be noted that a portion of the retaining member 32 and a portion of the flange member 36 define a continuous gap 40 therebetween within which the heads 42 of the bolts 34 securing the retaining member 32 to the casing 28 are disposed.

Because of such particular configuration of the flange member 36 and retaining member 32, it will be seen that the heads 42 of the bolts 34 cannot be reached because access thereto is blocked by the flange member 36. Thus, the retaining member 32 may be released from its state wherein it is secured to the casing 28 only upon release of the retaining member 32 from the casing 18. Removal of the bolts 38 to allow removal of the retaining member 32, it will be seen, also removes the bolts 38 from the casing 18, allowing the spring to extend to a state wherein the wall 20 and retaining member 32 are free of spring force thereon.

Counterbores 44 are provided in the retaining member 32 to prevent the securing of the casing 18 to the retaining member 32 if flange member 36 is not in place, The counterbores 44 are chosen to be approximately the same size as the heads of the bolts 38, which prevents the insertion of a wrench to tighten the bolts 38.

The remainder of the apparatus, similar to that disclosed in application Ser. No. 507,264, may then be installed.

ln accordance with the above description, ,upon removal of appropriate portions of the structure, the springretention arrangement may be disassembled by the removal of the bolts 38, which releases the retaining member 32 from the casing 18, allowing the spring 16 to extend to a state wherein the wall 20 and retaining member 32 are free of spring force thereon, and removing the bolts 34 to release the retaining member 32 from the casing 28.

It will thus be seen that the spring 16 is retained in an encapsulated state, and disassembly thereof which might lead to a dangerous condition is avoided, due to the fact that the preload on the spring 16 must be released before the arrangement can be disassembled.

What is claimed is:

l. A spring retention arrangement comprising:

a first casing within which the spring is disposed and defining a wall against which one end of the spring is positionable;

a second casing positioned generally about the first casing;

a retaining member;

casing only upon release of the retaining member from the first casing, allowing the spring to extend to a state wherein the wall and retaining member are free of spring force thereupon.

l5 2. The spring retention arrangement of claim 1 wherein the means associated with the retaining member comprise a flange member, and means for releasably securing the flange member to the retaining member so that the flange member substantially blocks ac 20 cess to the means for selectively securing the retaining member to the second casing when the flange member is so secured to the retaining member.

3. The spring retention arrangement of claim 2 wherein the means for selectively securing the retaining 35 member to the first casing comprise first bolt means and said flange member, the first bolt means being disposed through apertures defined by the flange member and retaining member and in threaded engagement with the first casing.

4. The spring retention arrangement of claim 3 wherein the means for selectively securing the retaining member to the second casing comprise second bolt means disposed through apertures defined by the retaining member and in threaded engagement with the 35 second casing.

5. The spring retention arrangement of claim 4 and further comprising means for preventing the securing of the retaining member to the first casing with the flange member removed from the retaining member.

6. The spring retention arrangement of claim 4 wherein a portion of the retaining member and a portion of the flange member define a gap therebetween within which the heads of second bolt means securing the retaining member to the second casing are dis- 45 posed, with the retaining member so secured to the first casing by the first bolt means and flange member.

7. A method of assembling a spring retention arrangement comprising:

positioning a spring in a first casing defining a wall;

positioning the first casing generally within a second casing; securing a retaining member to the second casing; compressing the spring within the first casing against the wall; securing the retaining member to the first casing; and

, releasing the compression of the spring to allow the spring to apply force to the wall and retaining member.

8. The method of claim 7 and further comprising the step of disassembling said spring retention arrangement comprising:

releasing the retaining member from the first casing,

to allow the spring to extend to a state wherein the a 

1. A spring retention arrangement comprising: a first casing within which the spring is disposed and defining a wall against which one end of the spring is positionable; a second casing positioned generally about the first casing; a retaining member; means for releasably securing the retaining member to the first casing, so that the spring is in a compressed state applying force to the wall and retaining member with the retaining member so secured to the first casing; means for releasably securing the retaining member to the second casing; and means associated with the retaining member for providing that the retaining member may be released from said state wherein it is secured to the second casing only upon release of the retaining member from the first casing, allowing the spring to extend to a state wherein the wall and retaining member are free of spring force thereupon.
 2. The spring retention arrangement of claim 1 wherein the means associated with the retaining member comprise a flange member, and means for releasably securing the flange member to the retaining member so that the flange member substantially blocks access to the means for selectively securing the retaining member to the second casing when the flange member is so secured to the retaining member.
 3. The spring retention arrangement of claim 2 wherein the means for selectively securing the retaining member to the first casing comprise first bolt means and said flange member, the first bolt means being disposed through apertures defined by the flange member and Retaining member and in threaded engagement with the first casing.
 4. The spring retention arrangement of claim 3 wherein the means for selectively securing the retaining member to the second casing comprise second bolt means disposed through apertures defined by the retaining member and in threaded engagement with the second casing.
 5. The spring retention arrangement of claim 4 and further comprising means for preventing the securing of the retaining member to the first casing with the flange member removed from the retaining member.
 6. The spring retention arrangement of claim 4 wherein a portion of the retaining member and a portion of the flange member define a gap therebetween within which the heads of second bolt means securing the retaining member to the second casing are disposed, with the retaining member so secured to the first casing by the first bolt means and flange member.
 7. A method of assembling a spring retention arrangement comprising: positioning a spring in a first casing defining a wall; positioning the first casing generally within a second casing; securing a retaining member to the second casing; compressing the spring within the first casing against the wall; securing the retaining member to the first casing; and releasing the compression of the spring to allow the spring to apply force to the wall and retaining member.
 8. The method of claim 7 and further comprising the step of disassembling said spring retention arrangement comprising: releasing the retaining member from the first casing, to allow the spring to extend to a state wherein the wall and retaining member are free of spring force thereon; and releasing the retaining member from the second casing. 